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1.3 Relative risks

Artificial feeding increases illnesses in infants by:

  1. denying the infant the many special, unique protective factors, both antibody and non-antibody, found in human milk
  2. exposing the infant to bacterial pathogens in other food sources
  3. not providing optimal nutrition, decreasing the infant's ablility to fight infections

Clinical Note:

To obtain true and fair scientifically-relevant results in research studies, the researcher must compare the variable being studied to the norm. For example: compare state of disease in adults who smoke (variable), to state of disease in adults who do not smoke (the norm). Results are then written up as a change from the norm - ie 'incidence of lung cancer is increased in those who smoke by X.'

Breastfeeding is normal and breastfed babies enjoy a NORMAL state of health. Studies of infant health are notoriously reported incorrectly, making statements that equate to 'Breastfed babies are healthier' whereas correct breastfeeding language should read 'Artificially-fed babies are sicker'.

Whenever you discuss feeding outcomes with your colleagues or with parents, ensure you are speaking factually using breastmilk and breastfeeding as the norm.

A little statistics...

Relative risk (RR) is a ratio of the probability of a disease, in this case, occuring in the experimental group (ie artificially-fed) versus the control (breastfed) group. The equation to work it out is: RR = Probability in experimental group divided by Probability in control group.

For example: If the probability of an infant contracting diarrhoea in the first month of life is 1% when breastfed, but 14% if artificially-fed then the RR=14. An artificially-fed infant has 14 times the risk of getting diarrhoea in the first month of life compared to the risk for a breastfed infant.

Acute diseases attributable to artificial feeding

Diarrhoea (diarrhea)

Dewey et al (1995)1 reported twice the incidence of gastrointestinal morbidity in artificially-fed infants in a relatively affluent community in the United States while Kramer et al (2001)2 reported a 66% increase in a socially advantaged group where artificial feeding was predominant.

In countries where poverty and poor hygiene are factors breastfeeding means the difference between healthy normal development, and malnutrition or possibly death.

Otitis media (middle ear infection)

A large literature review concluded that formula-fed infants' risk of otitis media is doubled in the first year.3 It has also been found that they experience a 75% increased incidence of otitis media of 10 or more days duration.1 Saarinen et al (1982)4 followed healthy term infants, noting that no exclusively breastfed infant suffered from otitis media in the first 6 months of life, while 10% of babies who were given any cow's milk did.

Pneumonia

The occurrence of pneumonia in infants living in poor socio-economic regions is significantly increased if they are artificially fed.5,6,7

A meta-analysis of research has found that artificial feeding contributed a 3.6-fold increased risk of hospitalisation for lower respiratory tract infections.8

Summary of diarrhoea, otitis media and pneumonia


The relative risk of developing diseases throughout life for artificially-fed as compared to human milk-fed infants. (Heinz Sight, 2001)9
0 - 1 month 1 - 12 months 1 - 6 years
Diarrhea 14 4 - 10
Otitis media 8.6 3.3 - 4.3
Respiratory illness 3.3 - 4.3

Urinary Tract Infection

Marild et al (2004)10 demonstrated a significant increase in UTI amongst artificially-fed infants in Sweden; this protection for the breastfed infant persisted after weaning.

Necrotising Enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in the NICU, with often devastating consequences.The key risk factors leading to NEC are prematurity, formula feeding, intestinal ischemia, and bacterial colonization.11 The mortality rate (15%-25%) for affected infants has not changed appreciably in 30 years.

Septicemia and Meningitis

Neonatal septicemia and meningitis is associated with severe morbidity and high mortality rates. Artificially fed infants in neonatal intensive care units, and artificially fed infants in developing countries, are most at risk.

In a comparison of breastmilk-fed and artificially-fed babies in neonatal intensive care units the incidence of sepsis was:12

Postnatal Age Breastmilk Fed Artificial Milk Fed
first 10 days 5% 10%
11 - 24 days 9% 20%
25 - 38 days 0% 15%

Chronic diseases attributable to artificial feeding

Type 1 Diabetes Mellitus (Insulin-dependent diabetes)

Type 1 diabetes is an auto-immune disease determined by a combination of genetic and environmental factors.

  • general population risk of developing Type 1 diabetes = 0.4%
  • when a first-degree relative is affected = 6%

Environmental factors provide the trigger that causes a child to develop diabetes.

There are several hypotheses as to what these environmental factors are:

  • early exposure to cow's milk protein
  • introduction to solid food before 3 months
  • not having all the protective benefits of breastmilk

Meta-analyses of the published research found a strong link between early introduction of artificial milks and the development of Type 1 diabetes:

  • exposure to cow's milk in the first 3 months13,14
  • children who breastfed <3 months, OR of 1.43 (1.15-1.77)15
  • no-breastfeeding increased the risk (OR=1.93 [95% CI: 1.33-2.80]), while breastfeeding for more than 12 months was protective (OR=0.42 [95% CI: 0.22-0.81]).16

The cycle of diabetic risk

Mothers who have type 1 diabetes are more likely to NOT breastfeed.17 Cesarian section birth, prematurity and unstable baby's condition at birth are among the reasons given for this occurrence. The same author also found that breastfeeding duration is likely to be shorter amongst this group of mothers with breastfeeding <4 weeks being associated with overweight at age 2 years.18

Can you see how the risk of type 1 diabetes can spiral through the generations? The birth and post-birth circumstances and management of the diabetic mother can lead to an intervention (ie. infant being not-breastfed/early exposure to cow's milk protein in artifical infant milk) which triggers the infant to later develop diabetes.

Would mothers put their baby at risk if they knew this?
What can you do at your workplace to help break this cycle?

Type 2 Diabetes

The mechanism is not entirely understood, however, studies report that formula-fed infants have higher basal and post-prandial concentrations of insulin and neurotensin.19,20 Being formula-fed in infancy is associated with a 1.6 fold risk of developing type 2 diabetes.21 22

Coeliac (Celiac) Disease

Celiac disease is an autoimmune enteropathy. Genetic susceptibility and dietary exposure to gluten are necessary for it to occur. Controlled studies looking at infant feeding have shown an approximately four-fold increased risk, as well as an earlier onset, among artificially fed children. 23

A meta-analysis of the literature 24 reported more than double the incidence of celiac disease in infants who received breastmilk substitutes before 6 months and were not receiving any breastmilk during the introduction of gluten-containing foods.

The current recommendation to prevent the development of celiac disease is for children to be breastfed exclusively for 6 months and for breastfeeding to continue while, and for several months after, gluten is introduced into the diet.

Obesity

Obesity is a serious condition that leads to chronic diseases such as heart disease, diabetes, hypertension, some cancers and an earlier death. Prevention of obesity starts at birth and is greatly influenced by the feeding method chosen.

Breastmilk contains an appetite regulator, leptin. Artifically-fed infants have half the normal serum leptin.25

Artificial feeding is significantly correlated with obesity in childhood and adulthood.26,27,28,3

Closely associated with childhood obesity:

  • early weaning to artificial infant formula
  • introduction of artificial infant formula before 6 months of age while breastfeeding
  • introduction of foods before 6 months of age

Childhood Cancer

Fortunately childhood cancers are rare, but their rarity makes quality research difficult to achieve.

There is a strong link between being artificially fed and the following cancers:29,30

  • acute lymphoblastic leukemia (leukaemia)
  • lymphomas - Hodgkin's and non-Hodgkin's
  • neuroblastomas

Inflammatory Bowel Diseases

  • Inflammatory bowel disease
  • Ulcerative colitis
  • Crohn's disease

The causes of these conditions are multifactorial. However, researchers have been able to link infant feeding method to their development, finding that cases were much more common in those who had been artificially fed.

Allergic Responses

Cow's milk is the most common single allergen affecting infants. The proteins in cow's milk are the allergen, NOT lactose. Standard infant formulas are made from cow's milk.

Compared to breastfed infants, artificially-fed infants have a significantly higher incidence of all forms of atopy.31Feeding soy-based artificial baby milk, compared to standard cow's milk-based artifical baby milk does not reduce the risk.32

Asthma, eczema, urticaria, rhinitis, failure-to-thrive, colic, chronic respiratory disease, gastro-oesophageal reflux and gastro-intestinal disease are all examples of conditions caused by an allergy or intolerance to cow's milk protein.

Workbook Activity 1.5

Complete Activity 1.5 in your workbook.

Developmental Deficits

Intelligence

The brain of the newborn infant continues to develop rapidly after full term birth, doubling in size by one year of age. The brain growth in the preterm infant is even more rapid and therefore has an even greater potential to be harmed by inappropriate nutrition.

Since Lucas in 199233 was able to demonstrate an intellectual deficit caused by artificial infant formula feeding, there have been numerous research papers confirming those findings.

Assessment of children at 6.5 years of age reveals:

  • exclusive artificial feeding, or early introduction of artificial infant formula, contributes significantly to

    • reduced total IQ
    • reduced verbal IQ
    • reduced performance IQ34

90% of children artificially fed will have an average 7-point IQ deficit that is directly attributable to being artificially fed.35

Sudden Infant Death Syndrome (SIDS)

Artificial feeding at one month of age was associated with double the risk for SIDS.36 The majority of babies older than one month who die of SIDS were infant formula fed. 37,38,39

A meta analysis of 23 SIDS studies revealed 19 studies which favourably supported breastfeeding in protection against SIDS. The combined analysis indicated that artificially-fed infants were twice as likely to die from SIDS.37

Think about it:

Most new parents do not know of the research that clearly demonstrates these poor health and developmental outcomes from artificial feeding. As a health professional do you feel it is fair to withhold this information from parents who generally just want to do the best thing for their children?

Who do you think is being protected when this information is not shared with parents? Who stands to lose by withholding this information? Who stands to gain by withholding this information?

But we shouldn't make mothers feel guilty!

Click on the icon above to read an article about making mothers feel guilty.

What would you say?

Well, have you thought about what you would say now if a mother said to you, "Is breastfeeding really worth all the effort it takes?"

In Module 3 you'll learn that discussing specific effects of breastfeeding and artificial infant formula feeding is required of you. However, the next module will help you to see how you can discuss this topic (and many others) giving

What should I remember?

  • the absence of breastmilk properties is the first contributing factor to disease processes
  • the exposure to artificial substances such as artificial infant milk has a strong association with acute and chronic illness
  • the acute conditions which are associated with infant formula feeding
  • the chronic conditions which are associated with infant formula feeding
  • there is a positive correlation between artificial infant formula feeding rates and the incidence of infant mortality and morbidity in every country in the World

Self-test Quiz

Assessment Quiz

When you are happy that you've understood all the information in this topic you will be ready to complete the Module 1 Assessment. To do this, go to the course opening page, scroll down to the Assessment section and choose Module 1.

Notes

  1. # Dewey KG et al. (1995) Differences in morbidity between breast-fed and formula-fed infants.
  2. # Kramer MS et al. (2001) Promotion of Breastfeeding Intervention Trial (PROBIT): a randomized trial in the Republic of Belarus.
  3. # Ip S et al. (2007) Breastfeeding and maternal and infant health outcomes in developed countries.
  4. # Saarinen UM (1982) Prolonged breast feeding as prophylaxis for recurrent otitis media.
  5. # Victora CG et al. (1987) Evidence for protection by breast-feeding against infant deaths from infectious diseases in Brazil.
  6. # Wright AL et al. (1989) Breast feeding and lower respiratory tract illness in the first year of life
  7. # Oddy WH et al. (2003) Breast feeding and respiratory morbidity in infancy: a birth cohort study
  8. # Bachrach VR et al. (2003) Breastfeeding and the risk of hospitalization for respiratory disease in infancy: a meta-analysis.
  9. # Heinz (2001-02) Heinz Sight: Infant Nutrition Newsletter
  10. # Marild S et al. (2004) Protective effect of breastfeeding against urinary tract infection
  11. # Yeo SL (2006) NICU update: state of the science of NEC.
  12. # el-Mohandes AE et al. (1997) Use of human milk in the intensive care nursery decreases the incidence of nosocomial sepsis
  13. # Kostraba JN et al. (1993) Early exposure to cow's milk and solid foods in infancy, genetic predisposition, and risk of IDDM.
  14. # Gerstein HC (1994) Cow's milk exposure and type 1 diabetes mellitus. A critical overview of the clinical literature.
  15. # Perez-Bravo E et al. (1996) Genetic predisposition and environmental factors leading to the development of insulin-dependent diabetes mellitus in Chilean children
  16. # Malcova H et al. (2006) Absence of breast-feeding is associated with the risk of type 1 diabetes: a case-control study in a population with rapidly increasing incidence
  17. # Hummel S et al. (2007) Breastfeeding habits in families with Type 1 diabetes
  18. # Hummel S et al. (2008) [Breastfeeding in women with gestational diabetes]
  19. # Lucas A et al. (1980) Breast vs Bottle: endocrine responses are different with formula feeding
  20. # Salmenperä L et al. (1988) Effects of feeding regimen on blood glucose levels and plasma concentrations of pancreatic hormones and gut regulatory peptides at 9 months of age: comparison between infants fed with milk formula and infants exclusively breast-fed from birth.
  21. # Ip S et al. (2007) Breastfeeding and maternal and infant health outcomes in developed countries
  22. # Horta BL et al. (2007) Evidence on the long term efects of breastfeeding:systematic review and meta-analyses
  23. # Davis MK (2001) Breastfeeding and chronic disease in childhood and adolescence
  24. # Akobeng AK et al. (2006) Effect of breast feeding on risk of coeliac disease: a systematic review and meta-analysis of observational studies
  25. # Savino F et al. (2004) Breast-fed infants have higher leptin values than formula-fed infants in the first four months of life
  26. # Baker JL et al. (2004) Maternal prepregnant body mass index, duration of breastfeeding, and timing of complementary food introduction are associated with infant weight gain.
  27. # Kalies H et al. (2005) The effect of breastfeeding on weight gain in infants: results of a birth cohort study
  28. # Li C et al. (2005) Additive interactions of maternal prepregnancy BMI and breast-feeding on childhood overweight
  29. # Shu XO et al. (1999) Breast-feeding and risk of childhood acute leukemia
  30. # Martin RM et al. (2005) Breast-feeding and childhood cancer: A systematic review with metaanalysis
  31. # Friedman NJ et al. (2005) The role of breast-feeding in the development of allergies and asthma
  32. # Ram FS et al. (2002) Cow's milk protein avoidance and development of childhood wheeze in children with a family history of atopy.
  33. # Lucas A et al. (1992) Breast milk and subsequent intelligence quotient in children born preterm
  34. # Gustafsson PA et al. (2004) Breastfeeding, very long polyunsaturated fatty acids (PUFA) and IQ at 6 1/2 years of age.
  35. # Caspi A et al. (2007) Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism
  36. # Vennemann MM et al. (2009) Does breastfeeding reduce the risk of sudden infant death syndrome?
  37. # McVea KL et al. (2000) The role of breastfeeding in sudden infant death syndrome
  38. # Alm B et al. (2002) Breastfeeding and the sudden infant death syndrome in Scandinavia, 1992-95
  39. # Horne RS et al. (2004) Comparison of evoked arousability in breast and formula fed infants.